112 CONTRIBUTIONS TO NORTH AMEKICAN ICHTHYOLOGY IV. 



a. llasal hr.mdiilu : N . : pharyn^-al teeth numerous, pectinate: inaxillaries 

 tormina part of tin- mar-in of the upper jaw < 'AH- TM.MII .!:. ::n. 



an. I'.avil lp|:uicliili\ als :t ; plnry n^eal te.-thfew; mar-in of upper jaw formed hy 

 premaxi Maries alone CYI-III MI >.!:. :'.!. 



' J'.raill ea-e IM't produced het Ween (il'hits : h:isl> i lailii dollldc, somiM imes wit 11 1I1US- 



cnlar canal; -1 to 1 superior pharyn^eal hones; lower jiharyn.^eals not falci- 

 fonn ; '' ha-.il hranehih\als; teet h iu jnw> ol'len piv-enl. ( ' V/; - eini.) 



FAMILY XXX. CATOSTOMID^E. 



(The Suckers.) 



r.ody oblong or elongate, usually more or less compressed. Head 

 more or less conoid. Opcrcles normally developed. Nostrils double. 

 No barbels. Mouth large or small, usually protractile and with lleshy 

 lips. Margin of upper jaw formed in the middle by the small preinax- 

 illaries, and on the side by the inaxillaries. Jaws toothless. Lower 

 pharyngeal bones falciform, armed with a row of numerous comb-like 

 teeth, r.ranchiostegals 3. Gill membranes more or less united to the 

 isthmus, restricting the gill-openings to the sides. Grills 4, a slit be- 

 hind the fourth. Pseudobranchia3 present. Scales cycloid, large or 

 small. Lateral line decurved, sometimes wanting. Head naked. Fins 

 not scaly. Dorsal fin comparatively long (of 11-.">0 rays), without true 

 spine. Anal I'm short. Caudal fin more or less forked. Ventrals ab- 

 dominal, with about 10 rays. Pectoral tins placed low, without spine. 

 No adipose tin. lielly not serrated. Alimentary canal long. Stomach 

 simple. No pyloric cceca. Air-bladder large, divided into two or three 

 parts by transverse constrictions, not surrounded by a bony capsule, 

 (ienera 11 or fewer; species about CO ; inhabiting the fresh waters of 

 N<>i ih America, two species in ICaslern Asia. They are not much valued 

 lishes, the llcsh being liavmless and full of small bone-. 

 -ioup r,it,isi< t ,,,'tn<i Ciinther, vii. I'J-'Jl.) 



* l>"r-al I'm rlon^alc, its drvclopcil rays -jri-MMu iiiinihcr ; air-lihnlili-r in two parts. 

 I '..ntaiicll.' pn-s.-iit ; hoily OVftte : si-airs laryv. (JliiliiiiicliH.i/inil'.) 

 <l. 1 I. ! -:il i 



/-. MOII III lar^i-, terminal, prof raet ile forwanls : lips thin ; pharynxeal bones a ml 



1 1 -ei 1 1 weak lc n< 1 1:1 s, .")'.!. 



l>l>. Month MM. iller, inferior, protractile downwards. 



il l>one> .siron^, (In- in-ill eoiMparatively eoarse ami lar^e. in- 



i- i -in;,' in size ilowm\ anl> 15ru \ i.icn rm s, 60. 



I'liaryii'/eal lou. > narrow, \\ilh the teeth thin and weak . . ( ' \ Ki-n .in:s, (il. 



ii la lie lie- oldilerali-d by the Union of the parietal hones; hody elongate, (fijclcp- 



liii' 

 d. Montli small, inferior, with thiek iiajiillose lips; scales rather small. 



L'YCLKPTL'S, 62. 



